This Rolls-Royce might be the most expensive new car ever built

Rolls-Royce Sweptail. Rolls-Royce At roughly $3 million, the Bugatti Chiron is one of the most expensive production cars to ever reach showrooms, so the words "affordable" and "Bugatti" rarely, if ever, occupy real estate in the same sentence. However, that's what happened over the weekend.

On Saturday, Rolls-Royce unveiled a one-off custom build called the Sweptail. At a reported price of nearly $13 million, it is believed to be the most expensive new car ever commissioned, The Telegraph reported.

While it may not be quite as pricey as the most expensive car of all time — the $38 million Ferrari 250 GTO — the Rolls is still the price of four brand-new Chirons.

For Rolls-Royce, the Sweptail represents a return to prominence of the brand's time-honored coach-building business.

Rolls-Royce

"Sweptail is the automotive equivalent of haute couture," Giles Taylor, the director of design for Rolls-Royce Motor Cars, said in a statement. "It is a Rolls-Royce designed and hand-tailored to fit a specific customer."

And it's the result of four years of work.

According to Rolls, a customer approached the company in 2013 and asked it to build a one-of-a-kind motor car inspired by the luxury yachts of the 1920s and '30s.

Rolls-Royce

The Sweptail's signature feature is a single-piece glass roof that tapers into the car's fastback rear end. It's a design feature that dominates the car's silhouette.

Rolls-Royce has not released technical specs of the car, but it's believed to be based on the current-generation Phantom platform, which means some version of the company's 6.75-liter V-12 is most likely lurking under its long bonnet.